The Israeli authorities have asserted that more aid trucks are entering the Gaza Strip, but humanitarian groups warn that bottlenecks are preventing relief supplies from reaching the most vulnerable people in the war-ridden territory.

Cogat, the Israeli security agency responsible for coordinating aid deliveries into Gaza, has said roughly 300 trucks of relief supplies and commercial goods have entered Gaza daily in recent days. And the price of some food items in markets has fallen significantly.

But United Nations officials said many trucks were still being intercepted by desperate people and gunmen before reaching their destination. Other obstacles, they said, are the limited routes into Gaza and long waits at Israeli checkpoints.

“There has been a slight improvement, but it hasn’t been sufficient to change the overall outcome,” said Olga Cherevko, a Gaza-based spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs.

In recent weeks, Israel has been pressured by allies to address growing hunger in Gaza after months of restrictions on the entry of aid. The Israeli government has responded by saying it would allow more trucks into the territory.

Last week, an Israeli security official, who spoke on condition of anonymity under military rules, said Israel was willing to facilitate the entry of 500 trucks per day and was trying to open more routes to let the United Nations and international organizations deliver relief.

“There is no limit on the number of trucks coming in,” said Roy Salamon, a Cogat spokesman.

Humanitarian officials have said the main solution to the crisis was “flooding the zone” every day until people do not feel they can obtain food only by swarming trucks. In July, less than 7 percent of trucks tracked by a U.N. mechanism supporting the aid effort arrived at their destinations.

On Wednesday, the United Nations Office for the Coordination of Humanitarian Affairs said that its teams in Gaza collected food and fuel at two crossings on Tuesday, but that some of its missions had been denied, impeded or canceled.

The start of the latest crisis dates back to early March, when Israel cut off all aid for Gaza, a move that Israeli officials said was taken to pressure Hamas into making concessions in cease-fire talks.

In May, a new aid delivery system run by American security contractors was established, but it has operated only four distribution centers, and hundreds of people have been shot dead on their way to the sites.

Despite the challenges of bringing aid into Gaza, prices in markets have seen a sharp decline. A kilogram of flour is now $4.14 compared with $11.83 two weeks ago, and a kilogram of sugar is $7.39 compared with $73.93, according to surveys conducted by the Gaza Governorate Chamber of Commerce and Industry.

Ayed Abu Ramadan, the chairman of the chamber of commerce, attributed the falling prices to an increase in the supply of aid and commercial goods sold in markets, but he emphasized that the prices were still well above prewar levels.

Many Palestinians in Gaza, he added, can no longer afford to purchase food, and others are buying only the absolute essential.